The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley,has recently invaded several Chinese regions,and continues to expand its range.This mealybug is a polyphagous insect pest,with at least 200 host pla...The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley,has recently invaded several Chinese regions,and continues to expand its range.This mealybug is a polyphagous insect pest,with at least 200 host plants from 63 families,including cotton,food crops,fruits,ornamental plants,tobacco,and vegetables.Here,we describe the first finding of P.solenopsis in Shandong Province,and investigate the abundances of its natural enemies(predator Coccinella septempunctata L.and parasitoid Aenasius bambawalei Hayat).All three species were detected from ornamental and weed species in Linyi,Shandong,in September 2018,and were positively identified using DNA barcoding.BLAST analysis revealed significant identity(99.38-100%) between sequences of P.solenopsis obtained in this study and those published in the past.This invasive pest represents a major potential threat to agri-horticulture in Shandong,which is a key province of China for production and export of many vegetables,flowers,fruits,and other crops.This mealybug species has a wide range of potential distribution in Shandong and is easily dispersed with agricultural and horticultural transport products.Further monitoring and management strategies are required to limit the spread of this pest species.展开更多
Mealybugs, such as Phenacoccus solenopsis, are highly sexually dimorphic. Winged adult males present such remarkable morphological differences from females that, to the untrained eye, conspecific adults of both sexes ...Mealybugs, such as Phenacoccus solenopsis, are highly sexually dimorphic. Winged adult males present such remarkable morphological differences from females that, to the untrained eye, conspecific adults of both sexes of P. solenopsis may be considered as two different insect species. A method to investigate sex-dimorphic mechanisms is by evaluating gene expression using RT-qPCR. However, the accuracy and consistency of this technique depend on the reference gene(s) selected. In this study, we analyzed the expression of 10 candidate reference genes in male and female P. solenopsis at different development stages, using common algorithms including the ?Ct method, NormFinder, geNorm, BestKeeper, and a web-based analysis tool, RefFinder. The results showed that EF1-β, RP-L32 and RP-18 S were selected as the most stable genes by both the ?Ct method and NormFinder; TUB-α was the most stable gene identified by BestKeeper; and RP-L40 and RP-L32 were the most stable genes ranked by geNorm. RefFinder, a comprehensive analysis software, ranked the ten genes and determined EF1-β and RP-L32 as the most suitable reference genes for the various developmental stages in male and female P. solenopsis. Furthermore, the two most suitable reference genes were validated by examining expression of the juvenile hormone acid O-methytransferase(JHAMT) gene. Results of the validation portion of the study showed that JHAMT expression was sex-biased towards males and exhibited a dynamic and classic expression pattern among the P. solenopsis developmental stages. The results can help further our knowledge on the molecular mechanisms underlying sexual dimorphic development in P. solenopsis.展开更多
The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an acc...The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.展开更多
Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang(Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrast...Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang(Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrastructure of four wax pores including trilocular,quinquelocular,and multilocular pores as well as tubular ducts,recording characteristics of their structure,size and distribution.We found that that the integument of the mealybug consists of three main layers-the procuticle,epidermis and basement membrane-and four sub-layers of the procuticle-the epicuticle,exocuticle,endocuticle and formation zone.The wax-secreting gland cells were closely arranged in epidermis.All of them were complex and composed of one central cell and two or more lateral cells.These complex cells possess a large common reservoir for collection and storage.Synthesized by the glandular cells,the wax is excreted outside integument through canals.展开更多
Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solen...Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solenopsis Tinsley emerged as a serious pest on cotton in India.Laboratory studies indicated that B.pallescens could feed on the cotton mealybug.Hence,further investigations were conducted to understand the stage of the predator which is most potential and the pest stage preferred by the predator.Mature nymphs and adults of B.pallescens could predate equally well on the neonates of cotton mealybug.Young (three to four-day-old) nymphs of the predator could not feed on any stage of the cotton mealybug.Mature nymphs (seven-day-old and above) and adults could effectively predate on both young and mature cotton mealybug crawlers,though preference was more for the younger crawlers.However,nymphs and adults of B.pallescens could not predate on the adult stage of the mealybug.Different predator:pest ratios were tested in cage studies and it emerged that B.pallescens adults released against the mealybug crawlers at a ratio of 1:5 and nymphal release at 1:10 caused maximum mortality of the mealybug crawlers.Considering the fast multiplication rate of cotton mealybug and the large number of predators which have to be released to manage them,further detailed studies are necessary on utilizing B.pallescens to target the neonates and younger stages of the cotton mealybug in field conditions.展开更多
Age-related declines in fertilization success have been reported for a wide range of species.The fertilization of parasitic wasps is closely related to egg production and sperm storage.Aenasius bambawalei(Hymenoptera:...Age-related declines in fertilization success have been reported for a wide range of species.The fertilization of parasitic wasps is closely related to egg production and sperm storage.Aenasius bambawalei(Hymenoptera:Encyridae)is a key parasitic wasp of the important invasive mealybug Phenacoccus solenopsis(Hemiptera:Pseudococcidae).The female offspring ratio of this parasitic wasp was declined with parental age in mass rearing under laboratory conditions.To investigate the molecular mechanisms involved in the reproduction of A.bambawalei,an extensive analysis of the impact of age on transcriptome profile of mated ovaries of this wasp was performed by comparing the gene expression profiles of various maternal ages:the early stage(ES),the intermediate stage(IS),and the advanced stage(AS).In total,358 differentially expressed genes were identified,with 17.60%(63 genes)of the changes associated with greater expression in fertilization.Moreover,the expression of serine protease 47 precursor,serine protease inhibitor 3/4,glucose dehydrogenase,fatty acyl-CoA reductase 1-like,major royal jelly,and acyl-CoA delta(11)desaturase-like was detected by real-time fluorescence quantitative(RT-qPCR).The results showed that fertilization related genes exhibited a stage-specific pattern.Egg production and sperm storage genes in A.bambawalei were significantly modified in the transcriptome,providing a starting point for the genetic dissection of fertilization.展开更多
基金supported by the National Key Research and Development Program of China(2017YFC1200600 and 2016YFC1201200)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(caascx-2017-2022-IAS)
文摘The globally invasive cotton mealybug Phenacoccus solenopsis Tinsley,has recently invaded several Chinese regions,and continues to expand its range.This mealybug is a polyphagous insect pest,with at least 200 host plants from 63 families,including cotton,food crops,fruits,ornamental plants,tobacco,and vegetables.Here,we describe the first finding of P.solenopsis in Shandong Province,and investigate the abundances of its natural enemies(predator Coccinella septempunctata L.and parasitoid Aenasius bambawalei Hayat).All three species were detected from ornamental and weed species in Linyi,Shandong,in September 2018,and were positively identified using DNA barcoding.BLAST analysis revealed significant identity(99.38-100%) between sequences of P.solenopsis obtained in this study and those published in the past.This invasive pest represents a major potential threat to agri-horticulture in Shandong,which is a key province of China for production and export of many vegetables,flowers,fruits,and other crops.This mealybug species has a wide range of potential distribution in Shandong and is easily dispersed with agricultural and horticultural transport products.Further monitoring and management strategies are required to limit the spread of this pest species.
基金supported by the National Natural Science Foundation of China(31270580)the Key Research and Development Program of Zhejiang Province,China(2018C02036)+1 种基金the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD19B06)the Special Fund for Agro-scientific Research in the Public Interest of China(201103026)
文摘Mealybugs, such as Phenacoccus solenopsis, are highly sexually dimorphic. Winged adult males present such remarkable morphological differences from females that, to the untrained eye, conspecific adults of both sexes of P. solenopsis may be considered as two different insect species. A method to investigate sex-dimorphic mechanisms is by evaluating gene expression using RT-qPCR. However, the accuracy and consistency of this technique depend on the reference gene(s) selected. In this study, we analyzed the expression of 10 candidate reference genes in male and female P. solenopsis at different development stages, using common algorithms including the ?Ct method, NormFinder, geNorm, BestKeeper, and a web-based analysis tool, RefFinder. The results showed that EF1-β, RP-L32 and RP-18 S were selected as the most stable genes by both the ?Ct method and NormFinder; TUB-α was the most stable gene identified by BestKeeper; and RP-L40 and RP-L32 were the most stable genes ranked by geNorm. RefFinder, a comprehensive analysis software, ranked the ten genes and determined EF1-β and RP-L32 as the most suitable reference genes for the various developmental stages in male and female P. solenopsis. Furthermore, the two most suitable reference genes were validated by examining expression of the juvenile hormone acid O-methytransferase(JHAMT) gene. Results of the validation portion of the study showed that JHAMT expression was sex-biased towards males and exhibited a dynamic and classic expression pattern among the P. solenopsis developmental stages. The results can help further our knowledge on the molecular mechanisms underlying sexual dimorphic development in P. solenopsis.
基金supported by the National Key R&D Program of China(2017YFC1200600,2016YFC1201200 and 2015BAD08A16)the Science and Technology Innovation Program of CAAS(caascx-2013-2018-IAS)
文摘The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.
基金National Natural Science Foundation of China(31070584)Natural Science Foundation of Shanxi Province(2010011042-1,2011021029-2)。
文摘Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang(Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrastructure of four wax pores including trilocular,quinquelocular,and multilocular pores as well as tubular ducts,recording characteristics of their structure,size and distribution.We found that that the integument of the mealybug consists of three main layers-the procuticle,epidermis and basement membrane-and four sub-layers of the procuticle-the epicuticle,exocuticle,endocuticle and formation zone.The wax-secreting gland cells were closely arranged in epidermis.All of them were complex and composed of one central cell and two or more lateral cells.These complex cells possess a large common reservoir for collection and storage.Synthesized by the glandular cells,the wax is excreted outside integument through canals.
基金financial support extended by the Cotton Mission Mode project TMC MM1 3. 3
文摘Blaptostethus pallescens Poppius (Heteroptera:Anthocoridae),which is amenable to mass rearing,has proved to be a potential predator of sucking pests like mites and thrips.Recently,the cotton mealybug Phenacoccus solenopsis Tinsley emerged as a serious pest on cotton in India.Laboratory studies indicated that B.pallescens could feed on the cotton mealybug.Hence,further investigations were conducted to understand the stage of the predator which is most potential and the pest stage preferred by the predator.Mature nymphs and adults of B.pallescens could predate equally well on the neonates of cotton mealybug.Young (three to four-day-old) nymphs of the predator could not feed on any stage of the cotton mealybug.Mature nymphs (seven-day-old and above) and adults could effectively predate on both young and mature cotton mealybug crawlers,though preference was more for the younger crawlers.However,nymphs and adults of B.pallescens could not predate on the adult stage of the mealybug.Different predator:pest ratios were tested in cage studies and it emerged that B.pallescens adults released against the mealybug crawlers at a ratio of 1:5 and nymphal release at 1:10 caused maximum mortality of the mealybug crawlers.Considering the fast multiplication rate of cotton mealybug and the large number of predators which have to be released to manage them,further detailed studies are necessary on utilizing B.pallescens to target the neonates and younger stages of the cotton mealybug in field conditions.
文摘Age-related declines in fertilization success have been reported for a wide range of species.The fertilization of parasitic wasps is closely related to egg production and sperm storage.Aenasius bambawalei(Hymenoptera:Encyridae)is a key parasitic wasp of the important invasive mealybug Phenacoccus solenopsis(Hemiptera:Pseudococcidae).The female offspring ratio of this parasitic wasp was declined with parental age in mass rearing under laboratory conditions.To investigate the molecular mechanisms involved in the reproduction of A.bambawalei,an extensive analysis of the impact of age on transcriptome profile of mated ovaries of this wasp was performed by comparing the gene expression profiles of various maternal ages:the early stage(ES),the intermediate stage(IS),and the advanced stage(AS).In total,358 differentially expressed genes were identified,with 17.60%(63 genes)of the changes associated with greater expression in fertilization.Moreover,the expression of serine protease 47 precursor,serine protease inhibitor 3/4,glucose dehydrogenase,fatty acyl-CoA reductase 1-like,major royal jelly,and acyl-CoA delta(11)desaturase-like was detected by real-time fluorescence quantitative(RT-qPCR).The results showed that fertilization related genes exhibited a stage-specific pattern.Egg production and sperm storage genes in A.bambawalei were significantly modified in the transcriptome,providing a starting point for the genetic dissection of fertilization.
